Electrophysiological and Behavioral Responses of a

Authors: Tania Sureda Carmen Quero Ma Pilar Bosch Rubén Avilés Francisco Coll Michel Renou Ángel Guerrero

Publish Date: 2006/09/15

Volume: 32, Issue: 10, Pages: 2177-2190

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Abstract

The sex pheromone of feral sweet potato weevils Cylas formicarius elegantulus from Cuba was found via solidphase microextraction analysis to be identical to Z3dodecenyl E2butenoate a previously reported compound Females emitted 20 pg pheromone d−1 In scanning electron microscopy studies carried out on the male antenna we identified several types of sensilla sensilla trichoidea of type 1 ST1 as long hairs 100–150 μm sensilla trichoidea of type 2 as short hairs 50–60 μm sensilla basiconica of type 1 as thick pegs 20–25 μm sensilla basiconica of type 2 as curved pegs 10–15 μm and sensilla basiconica of type 3 as thin and straight short pegs 15–20 μm The same types were observed in female antennae but ST1 were far less abundant than in males Sensilla chaetica were also found on the flagellum subsegments in both sexes In electrophysiological tests the crotonate function in the pheromone structure proved to be critical for activity since regular depolarizations 06–08 mV were obtained with puffs on 1 μg of the attractant but not with puffs of the formate acetate propionate or butyrate analogue of the pheromone In a double dualchoice olfactometer males showed maximum activity between the 4th and the 8th hr of scotophase at a dose of 50–1000 ng of pheromone In field tests a correlation between the contents of the ZE isomer in the pheromone formulation with activity was noticed and baits containing this isomer of stereomeric purity 94 showed the highest attractivity The presence of 5 of the ZZ isomer in the lure did not induce any synergistic or inhibitory effect and the alcohol precursor of the pheromone was inactive The results show that use of a stereomerically pure pheromone may not be necessary in pest control strategiesThe authors acknowledge MEC for a predoctoral fellowship to TS Subdirección General de Cooperación Internacional for a cooperative project with the University of La Habana and CICYT projects AGL 200306599C0201 PTR 19950656OP and Generalitat de Catalunya 2001SGR00342 for financial support

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